Semiconductor devices are used in a variety of applications, such as personal computers, cell phones, digital cameras, and many other portable electronic equipment. These portable electronic equipments need to be small, lightweight, and produced in high volumes at relatively low cost.
Semiconductor devices such as portable electronic equipments can be divided into a simple hierarchy consisting of devices such as integrated circuit (IC) dies, packages, printed circuit boards (PCB), and systems. The package is the interface between an IC die and a PCB. IC dies are made from semiconductor materials such as silicon. Dies are then assembled into a package. The packaged die is then attached either directly to a PCB or to another substrate, which may be a second level packaging. With the increasing demand for portable electronic equipments, there is a need for the development of smaller Integrated circuit (IC) packages with reduced footprint and height.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the preferred embodiments and are not necessarily drawn to scale.